The Pirates struck out 260 times in the month of July.
Upon a deeper dive, it gets worse.
In 26 games this past month, 260 different Pirates had nothing to show for their at-bat. That's an average of 10 a game, or 27.2% of all of their plate appearances (956 in total) over a month. Outside of a stretch from May 22 to June 21, 2013, no Pirates team has struck out that many times in a 26 game period. (The 2013 team technically hit this threshold four different times, but all in that same stretch.)
As far as single months goes, using FanGraphs' monthly splits tool (which dates back to only 2002, but likely covers the rest of the franchise's history given the spike in strikeouts league-wide this millennium), there have only been three other months where the Pirates racked up more strikeouts.